The European patent EP 1 840 549 B1 discloses protecting a device for detecting plugging of effective-pressure lines, wherein the device comprises two pressure sensors for detecting the time series of the static pressure in an effective-pressure line; a differential pressure sensor for detecting the time series of the difference between the pressures in the two effective-pressure lines; three calculation units for calculating the fluctuations of the two static pressures and the differential pressure based on the time series and the sums of squares of the fluctuations; and correlation-coefficient calculation units to determine the correlation coefficients between the time series for a static pressure and the differential pressure, and an evaluation unit, which detects plugging of the effective-pressure lines based on the correlations and identifies which of the effective-pressure lines is/are plugged.
Although the above approach to analyze fluctuations is purposeful as such, it is associated with considerable effort as two sensors in addition to the differential pressure sensor are required for the static pressure.